A configuration and operation of an LED light 1 according to the related art will now be described with reference to the accompanying drawing.
FIG. 1 is a cross-sectional view illustrating an LED light according to the related art.
The LED light of the related art includes an LED substrate 10 and a heat sink 20 mounted on the LED substrate 10 to radiate heat. Also, the LED light includes a fan 30 mounted on the heat sink 20 to feed air, and an inner tubular body 40 configured to receive the fan 30, through which the air flows to the fan from a top. In addition, the LED light includes an outer body 50 configured to house all of the components described above, of which a lower portion is opened, and a transparent plate 60 for covering the opened lower portion of the outer body 50.
The outer body 50 is provided with an inlet port 51 for sucking the air, and an outlet port 53 for discharging the air from an inside. The inlet port 51 is located at an upper portion of a side of the outer body, and the outlet port 53 is located at a lower portion of the outer body 50.
The LED substrate 10 is configured to be supported in the outer body 50.
The heat sink 20 is disposed so that radiation fins 23 face up. After the air sucked from the top by the fan 30 is fed to gaps between the radiation fins 23, the air is discharged to the side by the radiation fins 23.
A converter 70 is provided in the outer body 50 to convert an AC power to a DC power and supply it to the LED substrate 10.
Explaining the operation of the LED light 1 according to the related art, a power is applied to the LED substrate 10 and the fan 30, thereby turning on the LED mounted on the LED substrate 10 and operating the fan 30. The air sucked through the inlet port 51 by operation of the fan 30 is fed to the radiation fins 23 of the heat sink 20 from the fan 30 through the inner body 40. The air is discharged from the side of the radiation fins 23 through the outlet port 53. Therefore, since the air cools the heat sink 20 absorbing the heat from the LED substrate 10, it is possible to prevent the LED substrate 10 from overheating.
A part of the air sucked by the outer body 50 absorbs the heat from the converter 70, and then is fed to the radiation fins 23 to absorb the heat from the heat sink 20. After that, the air is discharged from the outer body.
The LED light of the related art has problems as follows.
First, its cooling efficiency is low. In other words, after the air fed to the radiation fins 23 by the fan 30 is discharged along the radiation fins 23, a part of the hot air is discharged through the outlet port 53, while other part moves upwardly and then is mixed with the cold air sucked through the inlet port 51. As a result, a temperature of the cold air is raised, and thus the cooling efficiency is lowered. Also, there is another problem in that the hot air discharged through the outlet port 53 is again fed to the inlet port 51, thereby further lowering the cooling efficiency. Since the above phenomenon is continuously repeated while the power is applying, the internal temperature of the outer body 50 is gradually raised, and thus a lifetime of the LED substrate 10 and the converter is shortened.
Also, since the heat sink 20 is provided, the whole weight of the LED light 1 is increased. Therefore, it is difficult to mount the LED light at a high point, such as a pole of a streetlamp or a ceiling, and a manufacturing cost is increased.